The present disclosure relates to apparatuses and/or methods for performing measurement in wireless communication systems.
Usage of terminals communicating with other devices through wireless signals (e.g., laptop computers, personal digital assistants (PDAs), mobile or cellular phones, or others) are more and more increasing. Terminals typically utilize various channels for different operation modes, respectively. Preservation of network resources, such as bandwidth, is becoming more important owing to usage of power-consuming applications, which are running on such terminals while being required to remain connected with a network. Terminals may be equipped with finite power sources (e.g., rechargeable batteries). Such finite power sources are required to operate terminals in various modes for a prolonged period of time.
A terminal may operate in one of diverse operation modes including a “connected mode” and an “idle mode.” The terminal in the connected mode may vigorously communicate data (e.g., voice or data calls or sessions) with one or more access nodes in a wireless communication system. A client terminal in the idle mode may monitor the paging channel (PCH) for paging messages or other control channels. Such paging messages may include messages for alerting the client terminal as to occurrence of an incoming voice or data call and/or control/overhead messages for transferring system information and other information about the client terminal.
The idle mode of a terminal may consume less power than the connected mode does. However, a terminal in the idle mode still consumes power for monitoring the paging channel. In order to reduce power consumption in the idle mode, paging messages may be transmitted to the client terminal through the paging channel at designated times. The client terminal may operate in a discontinuous reception (DRX) mode to monitor the paging channel periodically, not continuously, thereby decreasing power consumption. In the DRX mode, the terminal wakes up from a “sleep” state and enters an “awake” state to process the paging channel for messages, and unless additional communication is required, the terminal may enter back into the sleep state. One period during which the terminal repeats the “sleep” state and “awake” state may be termed a “DRX cycle.”
The terminal may perform measurement on frequencies in the idle mode. The measurement may include measurement on a downlink carrier frequency (intra-frequency) of a serving cell, measurement on a frequency (inter-frequency) different from the downlink carrier frequency, and measurement on a frequency (inter-RAT frequency) of a radio access technology (RAT) different from a RAT of the serving cell. Measurements of reference signal received power (RSRP) and/or reference signal received quality (RSRQ) may be taken for target frequencies. The terminal may carry out cell reselection based on a result of measurements for the frequencies in the idle mode.